While humans have unintentionally been altering Earth's climate for centuries, some scientists have begun to study how to intentionally hack the globe to cool the overheated planet.

Eli Kintisch's new book, Hack the Planet provides a thorough and nuanced portrait of the development of geoengineering. Through long acquaintance with the field's biggest names, Kintisch, a staff writer for Science, paints a deep sociological portrait of a radical new scientific discipline bursting messily into the world.

He reminds us that even though the techniques may be wild and global, many of the people dreaming them up are regular scientists trying to deal rationally with a carbon problem that they don't see society solving. Faced with a warming world, they are torn between watching nature die or trying to surgically kill it themselves.

Wired.com: What are some of the basic geoengineering options being discussed?

Eli Kintisch: The main geoengineering techniques fall into two basic categories: One, the ways to block sunlight at different points in the atmosphere and earth system to lower the temperature rapidly in that way, and the other is enhancing the planet's ability to take up carbon dioxide through a variety of techniques. So, sun-blocking and carbon-sucking are the two main ways.

With sun-blocking, what you are essentially doing is brightening the planet, increasing the earth's albedo. That can change the amount of total radiation that the planet experiences. Scientists have proposed ways of intercepting solar radiation at every single point from the surface of the earth by whitening roofs or brightening the ocean's surface itself with tiny bubbles, to brightening low-lying and high clouds, to one of the most radical and discussed geoengineering techniques: adding particles called aerosols to the stratosphere. That technique has many names, but I like to call it the Pinatubo option, because it was influenced by the rapid cooling that follows volcanic eruptions.

The Pinatubo option involves spraying some kind of particles (usually people talk about sulfur) into the upper atmosphere to form a kind of haze that blocks a small percentage of the sun's rays before they can enter the lower atmosphere.

The carbon methods involve generally enhancing natural systems to take in more carbon, perhaps genetically modifying plants so they have more carbonaceous cells or growing large blooms of algae in the ocean by using some sort of key nutrient that can catalyze and fertilize their growth. The main way has been to use iron. You could also build machines to suck in the carbon dioxide.

Wired.com: You pinpoint one moment as really touching off the latest interest in geoengineering: a paper by Paul Crutzen. Why was that paper so influential?

Kintisch: Scientists had considered mimicking the cooling effect that volcanic aerosols have on the planet for decades before Crutzen's paper. The scientist who first published on it was the Soviet scientist Budyko. But Crutzen came at a time where many scientists felt that the climate crisis was accelerating and he had the stature of a Nobel Prize. As an atmospheric chemist, he certainly had knowledge in this particular field.

And while he does have a reputation as a bit of a maverick, Crutzen's paper was assiduously spelled out and he sent it to all of the top minds in the field before publishing it. That made it hard to argue with his essential conclusion, which is that we better at least study the method. It was difficult for anyone to disagree with. The furthest people could go was arguing that the paper shouldn't be published. It was controversial and required intervention by the president of the National Academy of Science, Ralph Cicerone, an atmospheric chemist himself and friend of Crutzen.

Wired.com: Early in your book, you split the people working on geoengineering into two basic camps: the red team and the blue team. Who are these teams and how are they different?

Kintisch: First, I don't think anyone really wants to do geoengineering right now. Maybe a handful of people think we are at that stage or think it would be a good idea to "take control." But the [blue team] scientists who are starting to spend more of their time studying geoengineering are generally engineering types, the kinds of scientists who like to think up new solutions and create new ideas and synthesize existing ones. The red team scientists have more of the temperament of skeptics. They are better at shooting holes in proposals and identifying problems. For any field, you usually have these two types.

The blue team includes most famously Edward Teller [nuclear scientist and former head of Lawrence Livermore National Laboratory], who passed away in 2003, and his acolyte Lowell Wood. They are two of the blue team when it comes to the Pinatubo option. Then, when it comes to cloud-brightening, you have a British scientist named John Latham, who for most of his life has studied weather and came up with a way to brighten clouds. And when it comes to iron fertilization, which is growing algae blooms, there are a variety of scientists but most notably John Martin.

The red team includes scientists who have focused on the ways that these solutions could be deleterious, or on early technical problems with them. For the stratospheric aerosols, there is an expert on volcanoes, Alan Robock at Rutgers, who has focused on the problems with the Pinatubo option. For iron fertilization, there is an ecologist, Penny Chisholm at MIT, who is mostly focused on a variety of ecological and environmental issues related to growing these giant algae blooms.

Wired.com: One fascinating connection you draw is between scientists developing the atomic bomb and scientists working on geoengineering. "You hope to God this is never used but if you have to use it, you better know how it behaves," David Battisti tells you. That argument runs throughout post-war science. Does anyone have a better answer than the atomic scientists did?

Kintisch: At this point, a lot of scientists feel the cat is out of the bag. If anything, a desperate politician 30 years form now may suddenly decide, "I need to cool the planet." And if we don't study it, scientists won't have any way to warn this leader of what the consequences will be. From that perspective there is a Pandora's box that has been opened.

Geoengineering is a bad idea whose time has come. It is something that you have to study and hope to never use. [For the atomic scientists], the other side has nuclear weapons and they are pointed at you, so you have no choice but to develop a deterrent. In this case, the nuclear weapons are the unknown chance that the planet's sensitivity to CO2 is very high and will respond to some of these worst-case tipping points.

Scientist feel they have no choice but to develop this response that viscerally is almost sickening to many scientists, especially someone like David Battisti, who thinks a lot about the internal dynamics of the climate system and understands how hard it is to understand how the parts fit together and then predict its behavior.

Wired.com: We talk a lot about the "tails" of climate-change risk, the big, seemingly low-probability stuff that could have a major impact. Do we know what the tails of geoengineering schemes, particularly the Pinatubo option, are? Is there some slight chance that something really bad could happen?

Kintisch: For the most part, scientists are trying to focus their efforts on geoengineering ideas that have some natural analogue. The Pinatubo option mimics volcanoes. Cloud-brightening happens as a result of salt particles and dust.

But, we don't really know that much at all about any of these wild concepts. So, what scientists say is that the best way to make a decision is to compare not doing geoengineering and experiencing the worst-case scenarios of global warming with doing geoengineering and experiencing the tails or worst-case scenarios of geoengineering.

Often a mistake people make in talking about this, is that they consider that geoengineering schemes would work perfectly without weighing that there would be these unintended consequences.

Wired.com: Do you think it will be possible to design experiments that can address the risks and uncertainties of geoengineering?

Kintisch: I think in all areas of science involving risk, it's probably fair to say that there is no such thing as the perfect experiment that gives you the information you want and involves the least amount of risk. The best example is drug trials. People even die after a drug has been studied. In geoengineering, this gets down to how much information we will need to act in the future. We might be able with the Pinatubo option to understand more about the consequences on ozone. But we may not have thought to ask about other effects, like the impacts of diffuse light on various ecosystems. The larger you go [with experiments], the better the chance that you're going to discover the unknown unknowns. But the larger you go, the greater the risk that the studies themselves will have a deleterious effect.

Wired.com: One of your sources asks you, "If, say, a Huckabee administration suddenly woke up and started geoengineering the planet, what could anybody else do about it?" This seems like a real question. What would anyone else do about it?

Kintisch: I'm not an expert on international relations or nuclear brinksmanship, but I do think that we have no idea. One thing that makes that question hard to answer is that we don't know how severe the climate crisis would have to be before countries would consider unilateral geoengineering. Would there be food conflicts? Would there be problems with immigration? What other factors would be happening? Would it be a developing country with nuclear weapons or a coalition of nations?

This gets to the reason that scientists are meeting now in Asilomar. The worst- case scenario is, with any new risk, you don't want its existence or its use in the future to cause conflict in and of itself. One way to do that is to set up international norms and agreements that countries cooperate, and the technology itself won't become a flashpoint for conflict like what happened with nuclear weapons after WWII.

But the challenge for setting up rules for geoengineering is that scientists very rightly fear that if rules are set up right now, we might restrict research that might tell us things we need to know about geoengineering.

You don't want a free-for-all with everyone going out and trying geoengineering at a large scale out of fear or strategic reasons. But you have to do some studies to understand what those rules should be. And the scientists here in Asilomar are trying, at an early stage, to lay out voluntary guidelines to square that circle, and do some studies in the environment that could give us some early clues about the risk of geoengineering.

Wired.com: It seems like the toughest issue is having some sort of global governance structure in place. But if we got that in place, wouldn't we be most of the way toward a meaningful way to keep carbon in the ground?

Kintisch: That's an interesting point. If we can't get our act together to reduce by a relatively modest percent, this very dangerous trace gas that we're spitting into the atmosphere, it does suggest that we're going to have a lot of trouble regulating geoengineering.

One problem with geoengineering research that scientist Ken Caldeira has pointed out to me is that there are a lot of private companies who are involved in this research, who are out to do research but also to create a business around selling carbon credits. Is this a field that should be dominated by private enterprises?

I titled the chapter on the history of climate and weather modification as a pursuit of levers. Because what I think geoengineering comes down to is looking for levers, making small changes that have big effects in the climate system. And that's usually the goal of a company, they look for ways to profit off a small investment and yield big returns.

We're looking for good investments for our geoengineering buck, so it doesn't surprise that you'd have [private companies] Climos and Planktos interested in the very lucrative leverage involved in iron fertilization. And Nathan Myhrvold, inventor and close confidante of Bill Gates, interested in the stratospheric aerosols.

Wired.com: But is this an area where the work should be done just with national sponsorship?

Kintisch: Unlike most branches of Earth sciences, geoengineering is this kind of radically multidisciplinary idea. You take a supposed understanding of a basic system and develop an engineering method of altering or radically changing it. Generally, when it comes to developing real-world products, scientists come up with the kernel of the idea and companies have proven to be the best at turning the kernel into a working technology. In a way, I can see the allure of letting companies develop geoengineering ideas because they are set up to try different things and the allure of profits can drive new ideas.

That said, it is a really worrisome proposition that for-profit companies would be entrusted in developing techniques that might be deployed and have such far-reaching environmental or ecological consequences. That's why openness and transparency and scientific integrity is so important in this field.

Wired.com: You're heading to the Asilomar conference today on geoengineering. Do you see a scientist-led effort to regulate themselves internally as the best way of proceeding with small-scale research? Are they capable of that?

Kintisch: I think in other areas of science, researchers have shown that they are able to regulate themselves, at least initially. There is usually this tension between the scientists wanting to regulate themselves because they want a free hand in exploring a bunch of ideas, but then at some point having the officials come in.

It's such an early stage with geoengineering. Many of the people involved with it don't have experience working with dangerous things. They are Earth scientists or energy experts. They don't have the institutional experience that scientists in molecular biology have developed over the years.

And when it comes to molecular biology, there still are struggles between the community of scientists who study sensitive pathogens and governments. That community got started in regulating itself here in 1975.

It may sound like a lame answer, but there will be a continuous push and pull on geoengineering.

Wired.com: The biggest argument against geoengineering research raised by critics is that it causes delays in going after carbon emissions directly, and quite possibly will kneecap those efforts by providing political cover for big emitters. Do you think that's a strong enough argument to pull geoengineering off the table?

Kintisch: I don't think so. All the time we deal with moral hazard. We deal with it when it comes to insurance or people wearing seatbelts. As a society, we should be able to deal with the moral hazard of people understanding that geoengieering is a dangerous concept that has to be studied and should be kept as an absolute worst-case scenario, but that requires vigorous and public debate. It probably requires a more scientifically literate society than we have. When someone says a quick fix is available and you don't know much about geoengineering, you might easily be persuaded.

So, I think moral hazard is among the dangers of intervening on a larger scale with the planet, but like any of them, it shouldn't discount an idea that we have little choice but to look at.